The overall objective of this research is (1) to identify, isolate and characterize proteins on the mammalian plasma membrane which may be critical for cell specificity, particularly in differentiation and development of the neuro system and (2) to analyze the expression of mammalian genome which is unique to the nervous system. The first project is studied by analyzing the membrane proteins of rat nerve tissues (retina and brain) and surface exposed proteins of clonal neuro cell lines by a combination of immunological precipitation and two dimensional gel electrophoresis. The second project is studied by first measuring the extent of gene expression in rat brain in comparison with other tissues. The technique used is to use RNA excess hybridization to unique DNA to the saturation level. Distinctions between nuclear and cytoplasmic polyA attached, non polyA attached, different developmental stages, and different parts of the brain are the main concern at the moment. BIBLIOGRAPHIC REFERENCES: Lindstrom, D. M., S. Deeb and N. Sueoka (1976). "Transcriptional Complexity of rat tissues and tumor lines." J. Cell Biol. 70, 342a.